Electric heater



June 5, 1928.

F. H. MccQRMcK ELECTRIC HEATERl Filed Oct. l, 1927 inventor; Francis H. Mc Co'r'mick,

. um uw a HUMumMMMMMMMMMMMMNHN@-M ,UUUHUUUUD DEEE W E EEE E MEET m DEQ m Q n j -im m ,L mi m .-\m E .file .mw E mm 9 n EEEEEEEDED Q .DUDEEDDEE UDEM m .uuwknnnhunh HnuulwunhnHH"unhhhhh His Attorneg.

Patented June 5, 1928.

UNITED STATES FRANCIS H. MOCORMICK, QF GLEN ELLYN,

PATENT OFFICE.

ILLINOIS, ASSIGNOB TO EDISON ELECTRIC APPLIANCE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

nnnc'rmc HEATER.

Application led October 1, 1927. Serial No. 223,424.v

My invention relates to electric heaters, more particularly to electric heaters of the radiant type, and has for its object the provision of a simple and reliable heater of this character. v

.In carrying out my invention, I provide a support for the heating resistor comprising a plurality of elongated heat refractory members rovided with overhanging projections. `Tllfese members are assembled in alternate relation to form a support so that the projections point in opposite directions in zig-zag relation and secure a heating resistor which extends between them.

For a more complete understanding/'of my vention, reference should be had to the accompanying drawing in which Fig. 1 is a plan view of an electric heater embodying my invention; Fig. 2 is a fragmentary elevation view of the device shown in Fig. 1; Fig. 3 is a sectional view along the line 3-3 of Fi 2 looking in the direction of the` arrows; w ile Fig. 4 is a fragmentary perspective view showing the supportin. members..

Referring to the drawing, I have shawn my invention in one form as applied to awall type radiant heater, i. e., a heater which is arranged to be mounted in an opening or recess provided for it in the wall of a build-i" ing. Ars shown the heate'r comprises an open front metallic casing 10 which is set in an opel-iin in the wall. Ametallic supporting brac et issecured in this casing,

this bracket com rising a substantially vertical smaller bac member 11, which is arranged inspaced relation with the back wall l' of the casing '10,togethery with an up er member 12 which is joinedto the mem er l11 at the top and extends' from the portion 11 in anA upwardly inclined directionto a point substantially opening of the cas1ng`10, a Ventilating yspace 13 being provided between the member 1 2 and the top of the casing. As indicated in Fig. 1, the vertical portion 11 is considerably smaller in width in' a horizontal direction, and also in height, than the casing. Side members 14 and 15 are secured to the sides of the member 11, respectively, and extend toward the front of the casing in diverging relation. At. their outer edges these side members '14 andv 15 are secured to the side walls of. the casing by means of brackets flush with the frontv 16 and 17. The member 12 is secured atl each end to the u per ends of the side members 14l and 15. bottom member 18 is also provided, this member having a flange at the back by means of'which it is secured to the back member 11 and at each end it is flanged and secured to the side members 14 and 15.

The bracket thus Aformed in the casing provides a support for an electric heating unit. This heating unit comprises a support formed from a plurality of elongated electricall insulating blocks 19 stacked horizonta ly upon each other and rovided with curved sides which are place toward the front of the casing, as indicated in Fig. 1-. These blocks are stacked on the bott'om member 18 and clamped between the bottom member and a flange 20 on the up er end of the back member 11 by means ofp a bolt 21 which' passes through central apertures in the blocks. struction and are preferably molded from heat refractory electrically insulating material. They are each provided with a lurality of hooks in their front curved sldes It will be observed that these hooks are formed by making suitable recesses 22 in a rib 23 which extends lengthwise on the The blocks are identical in con-A curved front side of the block and centrally thereof, these recesses being provided lwith overhanging side walls 24 pointing toward 'the sam'e end of the block. Between therecesses forming the hooks are strengthening ribs 25. The recesses, furthermore, are equally spaced and the series of recesses begins nearer one end of the block than the other, whereby the blocks may be stacked in alternate or reverse relation so that thehooks point in opposite directions and are in zigzag relation in' a transverse direction. A helical yresistancemonductor -26 is threaded up and down through theseseries of zigzag recesses in a pluijalityof vertically extending lengths eachd of 'which extends in a zigzag manner across the support.

In orderY to further secure the blocks they are each provided at one end with a. transverse aperture 27 and at the other end.4 with projections-or protuberances 28 and 29 on opposite sides. These holes and protuberances are spaced equal distances" from the central aperture 30 --for the bolt 21 so that when the blocks are stacked in reversed lvided for them in the the terminal leads 33 connected to the ends.

of the heating resistor, the apertures extending through the ,projections 32 which therebyconstitute insulating sleeves for the terminal leads. The terminal leads are connected to a control switch- 34 which is mounted on a front plate 35 and secured at its corners by bolts 36 tothe casing 10. The switch is provided with an operating lever 37 which projects throu h an aperture in the plate 35 whereby tigre switch may be operated from the front of the plate.

The plate 35 is provided with Ventilating apertures 38 at the bottom which communicate with the space formed between the bottom member 18 and the bottom of the casing whereby air is free to enter through these apertures and iiow upward between the back member ll'and the casing to the space 13 where it flowsv out through a series of aper- -tures 39 provided in the front plate. This provides for a circulation of cooling air around the back, top, bottom and sides of the bracket supporting the heating unit whereby the casing 10 is maintained at a sufficiently low temperature to prevent any tire hazzard. A Abaille plate 40 is preferably secured to the back wall of the casing in spaced relation therewith and also in spaced relation with the back wall 11 of the bracket. In order to still further reduce the operating temperature of the casing, a sheet of heat insulating material 41, such as asbestos, is secured to the top member '12 of the bracket on its Vtop or inner side and also a similar sheet of insulating material 42 is secured to the inside of the casingv at the top thereof.

The front plate 35 is, furthermore, provided with a plurality of apertures 43 in a central portion 44 just in front of the heating unit, this central portion 44 having `sub-- stantially the same area as the front opening of the supporting bracket for the heating unit. This central portion extended outward and, as shown, is formed as a separate member which is secured to the front plate 1n an. opening therein provided for it. The front plate and portion 44 thus constitute a grating covering the front of the casing.

While I have described my invention as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that I do not limit my invention thereto since various modifications thereof will suggest themselvesv to those rality of elongated heat refractory members provided with overhanging projections pointing lengthwise thereof, said members being arranged in reversed relation, and a heating resistor secured by said projections extending in a zigzag path transversely of said members.

2. An electric heater comprising a pluralit of elongated heat refractory members, a ri on each of said members extending lengthwise thereof, said rib Vbeing provided with recesses havingoverhanging Walls and said members being arranged side by side with said recesses in zigza relation, and a resistance conductor exten ing crosswise of said members in zigzag relation between said recesses. y

3. An electric heater comprising a lurality of elongated heat refractory mem ers provided with overhanging projections pointing lengthwise thereof, said members being arranged in reversed relation, a heating resistor secured by said projections extending in a zigzag path transversely of said members, an open front casing, a bracket" secured to said casing on which said members are secured in spaced relation to the top, bottom and back walls of said casing so as to provide for' the circulation of cooling air between said support and said casing, and a grating over the front of said casing.

4, An electric heater comprising a support formed from a plurality of elongated heat; refractory members provided with a projection on each' side at one. end and an aperture in the opposite end, said members being stacked in reversed relation so that the projections on one member lit in the apertures in the two adjoining members, a rib on each of said members extending lengthwise thereof, said rib being provided with equally spaced recesses having overhanging walls pointing toward one end of said member and said recesses being nearer one end of said member than the other, whereby said overhanging walls in the assembled support point in opposite directions and are in staggered relation in a transverse direction, 'and a resistance conductor extending across said members and secured by said overhangingA y walls.

. in the opposite end, said members being stacked in reversed relation so that the projections on onemember fit in the apertures 1n the two adjommg members, a rib on each l lo of said members extending lengthwise thereof, said rib being provided with equally spaced recesses havingr overhanging walls pointing toward one end of said member, said recesses' beingr nearer one. end ot said member than the other whereby said overhanging Walls in the assembled support point. in opposite directions and are in staggered relation in a transverse direction, a resista-nee conductor extending across said members and secured by said overhanging Walls, an open front casing, a bracket se cured to said casing on Whlch said support is mounted in spaced relation to the top,l

bottom and back Walls of said casin so as to provide for the circulation of cooling air between said support and said easing, and a grating over the front of said casing.

In Witness whereof, I have hereunto set my hand this 26th day of September, 1927.

FRANCIS H. MCooRMIcK. 

